62 QUADRUPEDS OF MASSACHUSETTS. 



Dimensions. 



in. t'tlis. 



Whole length, (3 



Head, from the nose to the ears, 10 



Tail, 2 5 



Longest of the whiskers, 15 



Observations. This beautiful animal inhabits meadows and 

 wooded places. It is often seen in fields recently mowed, and is 

 known by the name of Deer Mouse, in which is also included the 

 Gerbillus or Jumping Mouse. Our animal, though it leaps well, 

 yet cannot take such long and rapid strides as the true Jumping 

 Mouse. It is, however, quite active, and difficult to capture. 

 It is probably native, and originally inhabited woods and woody 

 places, but has now taken up its abode in places where grain and 

 seeds of grass are plentiful. It appears to be the connecting link 

 between the Arvicola and Gerbillus, having quite a long tail, and 

 stout posterior extremities. 



Genus Mus. Lin. 



Generic characters. Dental system ; incisors | ; canines f^^ ; 

 molars ~~ ; = 16 ; grinders simple, with tubercular summits ; 

 superior incisive teeth wedge-shaped ; inferior compressed and 

 pointed. Tail nearly naked, annulated with scales. 



1. Mus musculus. Lin. The Common Mouse. 



Common Mouse, Pennant, Brit. Zool., i. p. 122. 



Mus domesticus vulgaris, minor, Ray. 



The Common Mouse, Godinan, Nat. Hist., ii. p. 84. 



Specific characters. Fur brownish ash above, light ash beneath ; 

 tail rather shorter than the body ; ears about half the length of the 

 head. 



Description. Head tapering ; muzzle acute ; ears rounded ; 

 ears, feet, and tail clothed with only a small quantity of hair ; 

 eyes prominent and bright ; whiskers numerous, extending in 

 graceful lines around the head. It has four digits on its anterior 

 feet, and a rudimental thumb destitute of a claw ; on the hind feet 

 there are five. 



